The invention relates to a flow-turning device and to a method for producing internally geared wheels using two sets of internal toothing arranged axially one behind the other, at least one of which is a helical toothing. By helical toothing is also to be understood a screw thread.
Internally geared wheels having sets of internal toothing that are made of steel alloys and other metallic materials are used in particular for power transmission in driven wheels of heavy goods vehicles or tractors, for example. Internally geared wheels of this type have at their forward ends sets of internal toothing that are accessible from the outside. The two sets of internal toothing can have a different diameter if the internally geared wheel is to be used in a gearbox, for example. The internally geared wheel can have a spur toothing, in which the teeth extend parallel to the axis of rotation, or a helical toothing or screw thread.
WO 96/20050 describes a method for producing internal geared portions, in which method internally geared wheels having two sets of internal toothing are produced as a result of pressure rollers flow-turning the workpiece over shaping tools. In this connection, however, only internally geared wheels having spur toothing on both sides can be produced.